"Blank nodes in DELETE templates act as "wild cards", effectively as variables bound to all RDF terms; the same blank node cannot be used in the WHERE clause and the template, or in multiple BGPs, SteveH, dcharbon2, LeeF abstaining "

15:22:51 [AxelPolleres]

DELETE { ?X :knows [] } WHERE {...}

15:22:51 [NickH]

AxelPolleres: the idea is that bnodes can act as wildcards

15:23:19 [NickH]

AxelPolleres: there has been quite a bit of disccussion about this on email